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<TITLE>[Chapter 28] 28.9 java.net.HttpURLConnection (JDK 1.1)</TITLE>
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<DIV CLASS=sect1>
<h2 CLASS=sect1><A CLASS="TITLE" NAME="JNUT2-CH-28-SECT-9">28.9 java.net.HttpURLConnection (JDK 1.1)</A></h2>

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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-28-SECT-9.1"></A></h3>
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<P CLASS=para>
This class is a specialization of <tt CLASS=literal>URLConnection</tt>.  An
instance of this class is returned when the
<tt CLASS=literal>openConnection()</tt> method is called for a <tt CLASS=literal>URL</tt>
object that uses the HTTP protocol.

<P CLASS=para>
The many constants defined by this class are the status
codes returned by HTTP servers.  <tt CLASS=literal>setRequestMethod()</tt>
specifies what kind of HTTP request is made.  The
contents of this request must be sent through the
<tt CLASS=literal>OutputStream</tt> returned by the
<tt CLASS=literal>getOutputStream()</tt> method of the superclass.  Once an
HTTP request has been sent, <tt CLASS=literal>getResponseCode()</tt>
returns the HTTP server's response code as an integer, and
<tt CLASS=literal>getResponseMessage()</tt> returns the server's response
message.  The <tt CLASS=literal>disconnect()</tt> method closes the
connection, and the static <tt CLASS=literal>setFollowRedirects()</tt>
specifies whether URL connections that use the HTTP protocol
should automatically follow redirect responses sent by HTTP
servers.

<P CLASS=para>
In order to successfully use this class, you need to
understand the details of the HTTP protocol.

<DIV CLASS=screen>
<P>
<PRE>
public abstract class <tt CLASS=literal>HttpURLConnection</tt> extends URLConnection {
    // <tt CLASS=literal>Protected Constructor</tt>
            protected <tt CLASS=literal>HttpURLConnection</tt>(URL <tt CLASS=literal>u</tt>);
    // <tt CLASS=literal>Response Code Constants</tt>
            public static final int <tt CLASS=literal>HTTP_ACCEPTED</tt>, <tt CLASS=literal>HTTP_BAD_GATEWAY</tt>, <tt CLASS=literal>HTTP_BAD_METHOD</tt>;
            public static final int <tt CLASS=literal>HTTP_BAD_REQUEST</tt>, <tt CLASS=literal>HTTP_CLIENT_TIMEOUT</tt>, <tt CLASS=literal>HTTP_CONFLICT</tt>;
            public static final int <tt CLASS=literal>HTTP_CREATED</tt>, <tt CLASS=literal>HTTP_ENTITY_TOO_LARGE</tt>, <tt CLASS=literal>HTTP_FORBIDDEN</tt>;
            public static final int <tt CLASS=literal>HTTP_GATEWAY_TIMEOUT</tt>, <tt CLASS=literal>HTTP_GONE</tt>, <tt CLASS=literal>HTTP_INTERNAL_ERROR</tt>;
            public static final int <tt CLASS=literal>HTTP_LENGTH_REQUIRED</tt>, <tt CLASS=literal>HTTP_MOVED_PERM</tt>, <tt CLASS=literal>HTTP_MOVED_TEMP</tt>;
            public static final int <tt CLASS=literal>HTTP_MULT_CHOICE</tt>, <tt CLASS=literal>HTTP_NOT_ACCEPTABLE</tt>, <tt CLASS=literal>HTTP_NOT_AUTHORITATIVE</tt>;
            public static final int <tt CLASS=literal>HTTP_NOT_FOUND</tt>, <tt CLASS=literal>HTTP_NOT_MODIFIED</tt>, <tt CLASS=literal>HTTP_NO_CONTENT</tt>;
            public static final int <tt CLASS=literal>HTTP_OK</tt>, <tt CLASS=literal>HTTP_PARTIAL</tt>, <tt CLASS=literal>HTTP_PAYMENT_REQUIRED</tt>;
            public static final int <tt CLASS=literal>HTTP_PRECON_FAILED</tt>, <tt CLASS=literal>HTTP_PROXY_AUTH</tt>, <tt CLASS=literal>HTTP_REQ_TOO_LONG</tt>;
            public static final int <tt CLASS=literal>HTTP_RESET</tt>, <tt CLASS=literal>HTTP_SEE_OTHER</tt>, <tt CLASS=literal>HTTP_SERVER_ERROR</tt>;
            public static final int <tt CLASS=literal>HTTP_UNAUTHORIZED</tt>, <tt CLASS=literal>HTTP_UNAVAILABLE</tt>, <tt CLASS=literal>HTTP_UNSUPPORTED_TYPE</tt>;
            public static final int <tt CLASS=literal>HTTP_USE_PROXY</tt>, <tt CLASS=literal>HTTP_VERSION</tt>;
    // <tt CLASS=literal>Protected Instance Variables</tt>
            protected String <tt CLASS=literal>method</tt>;
            protected int <tt CLASS=literal>responseCode</tt>;
            protected String <tt CLASS=literal>responseMessage</tt>;
    // <tt CLASS=literal>Class Methods</tt>
            public static boolean <tt CLASS=literal>getFollowRedirects</tt>();
            public static void <tt CLASS=literal>setFollowRedirects</tt>(boolean <tt CLASS=literal>set</tt>);
    // <tt CLASS=literal>Public Instance Methods</tt>
            public abstract void <tt CLASS=literal>disconnect</tt>();
            public String <tt CLASS=literal>getRequestMethod</tt>();
            public int <tt CLASS=literal>getResponseCode</tt>() throws IOException;
            public String <tt CLASS=literal>getResponseMessage</tt>() throws IOException;
            public void <tt CLASS=literal>setRequestMethod</tt>(String <tt CLASS=literal>method</tt>) throws ProtocolException;
            public abstract boolean <tt CLASS=literal>usingProxy</tt>();
}
</PRE>
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<DIV CLASS=sect2>
<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-28-SECT-9.2">Hierarchy:</A></h3>

<P CLASS=para>
Object->URLConnection->HttpURLConnection

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